Respiration apparatus



June 21, 1938.

E. E. W. ANDERSON ET AL RESPIRATION APPARATUS Filed A ril 1, 1935 therespiratory action. The respiration muscles pressed. to ether.

sion must be compensated for by increasing the Patented June21, 1938UNITED STATES PATENT OFFICE aEsPmA'moN APPARATUS Emil Einar WilhelmAnderson and Georg Karl Vilhelm Johanson, Lidingo, Sweden, assign'ors toSvenska Aktiebolaget Gasaccumulator, Stockholm, Sweden, a corporation ofSweden Application April 1, 1935, Serial No. 13,996'

In Sweden April 5, 1934 16 Claims. (Cl. 128--29) Our invention relatesto artificial respirators, branch conduit must be forced down before theand especially to apparatus of this type which is exhaling gas canescape. suitable for maintaining respiration during sur- In this kind ofapparatus the inhalation is gical operations on the lungs of a patient.effected in such a way that the patient reduces Broadly, there are twotypes or kinds of resthe pressure in the lungs by means of therespiration apparatus, the first being employed to piration muscles tosuch an extent that gas from revive persons who are apparently dead, andthe the apparatus flows thereinto. second being used for sustainingrespirationdur- Both these types of respiration apparatus are, ingoperations. however, of no use for more complicated opera- In therespiration apparatus used to revive pertions on lungs, especially foroperations -in which sons who are apparently dead, an injector is used,the chest is entirely or partly cut open so that the pressure andsuction sides of which, respecthe respiration muscles do not functionsatisfactively, are connected alternately with the inhaltorlly or evendo not function at all, ing conduit'. Apparatus of this kindconsequently Successful use of the foregoing type of respiraoperates sothat air or oxygen gas is forced into tion apparatus is possible only ifthe operation the lungs up to a definite pressure, whereupon alfects butone of the lungs and only if such the gas is sucked out until a pressuresomewhat operation may be rapidly performed. It the opbelow atmosphericpressure is obtained. 'I'hereeration is of longer duration it isprobable that upon, the cycle is repeated. the patient will die becausethe respiration pro- The apparatus hitherto used for sustaining resceedsat greatly reduced efficiency. This is bepiration during operations hasrelied on the in-- cause the opened lung does no work, but serves halingmuscles of the patient continuing to work as an equalizer for the otherlung, so that only and the patient himself doing all or most of theone-half of the gas inhaled by the other lung respiration. Respirationapparatus of this kind consists of fresh air, while the other halfconsists supplies the gas to the lungs in a continual curof consumed airfrom the lung being operated rent, but when the patient exhales, meansare upon. In the most complicated cases when both provided for passingthe gas through a branch the pleural sacs must be opened,there ispracconduit. A resistance to flow is placed in this tically no chance ofthe patient surviving. In branch conduit or at the outlet thereof, sothat such cases the second of the above mentioneda predeterminedpressure is necessary for flow types of respiration apparatus is whollyuseless to take place therethrough. because the motive power required isfurnished This is necessary on account of the nature of by therespiration muscles of the patient. The first type of respirationapparatus cannot be used in this case either, as it works at a neutralrespiration pressure level, and hence, as soon as the pleural sacs areopened, the lungs shrink.

One of the objects of our present invention is to provide a respirationapparatus in which the inhalation is effected by forcing gas into thelungs during a period of increasing elastic tension oi. the lungs, andthe exhalation is effected by letting gas out during a period ofdecreasing elastic tension of the lungs. In both cases, however, apositive minimum pressure, adjustable from case to case, is maintainedwhich allows an exhalation from the patient without relying on his ownrespiration action.

A further object of our invention is the provision of apparatus of theabove type in which do not influence the lungs directly, but act uponthe pleural sacs so that these expand or are Hence, there arises apartial vacuum or an excess of pressure between the pleural sac and thelung which results in inhalation or exhalation from the lung in order toequalize the pressure. The lung therefore lies more or less as anexpanded elastic bladder within the pleural sac. The elastic tension inthe lung is normally equal to to mm. of water column. In order toprevent the lung from shrinking or collapsing when the. chest is openedduring an operation, the lung's own tenrespiration pressure level anamount corresponding to the above elastic tension of the lung. I

Usually the positive respiration pressure is produced by submerging theoutlet of the branch conduit a suitable depth below the surface of aliquid so that the column of the liquid from the surface down to theoutlet of the exhalation or the period of the artificial respiration isnot scious reaction of the patient against a wrong periodicity.

Further objects and advantages of our invention will be apparent fromthe following description, considered in connection with theaccompanying drawing which forms part of this specification and which isa cross-sectional view of a preferred embodiment of our invention.

In the figure, reference character I indicates a cylinder containinggas, such as oxygen. A pressure reducing valve 2, pressure governor 3and an equalizer 4 are interposed in the conduit leading from thiscylinder. The, gas contained in cylinder is under high pressure andvalve 2 is a standard reducing valve for reducing the pressure of thegas passing therethrough. Pressure governor 3 is provided with valvemechanism controlled by a spring-pressed diaphragm and serves tomaintain the pressure of the gas on the discharge side thereof at aconstant value. Equalizer 4 comprises a chamber having an appreciablevolumetric capacity bounded by a spring-pressed diaphragm and serves asa surge chamber to prevent sudden fluctuations in pressure which mightoccur too rapidly to be equalized by pressure governor 3. From theequalizer 4 a supply conduit 5 leadsto the main valve chamber 1 of theapparatus, a throttle valve 6 being interposed in the conduit. The valvechamber 1 contains an inhalation valve 8 and an exhalation valve 9, thevalve members of which are connected with each other by means of aspindle |2 to which is also connected a quick action mechanism arrangedin the pressure chamber Ill. Mechanism may consist of any pressureresponsive snap action device and, as shown, comprisestwo leversconnected to each other, the outer ends of said levers being connectedto fixed points on the walls of chamber I0. One of these levers 49includes a spring 50, interconnected between its two parts, the otherlever 5| being connected to the spindle I2 and by means of spring 52 tothe diaphragm 53, this latter being under pressure from spring 54. Ifthe pressure in chamber I is increased, diaphragm 53 will slowly moveagainst pressure of spring 54, thereby increasing the tension of spring52. At a certain pressure this tension is equal to the component alongthe spindle |2 of the pressure from spring 50. Upon further increase ofpressure in chamber lit-the tension in spring 52 will cause lever tomove upwardly, therebycausing the angle between the levers to approach180 and giving rise to a very rapid decrease of the said component ofpressure from spring 50. The diaphragm 53 being balanced by springs 52and 54 during this movement also moves upwardly, thus maintainingtension in spring 52. The spindle |2 therefore suddenly will snap to itshighest position. The reverse is true upon a reduction in pressure. Itwill thus be apparent that valves 8 and 9 have no intermediatepositions, but are either fully open or closed. Between the valvechamber 1 and the pressure chamber ID a check valve I3 is arranged- I8by means of a conduit H, the chamber between the valve 8 and the wall I8is connected with the supply conduit 5, and the chamber between the walll6 and the valve 9 is connected with the exhalation valve housing 20 bymeans of a conduit l9. Both the inhalation valve housing l8 and theexhalation valve housing 20 are each divided into valve chambers 2| and22, respectively, and diaphragm chambers 23 and 24, respectively. Thetensions of the diaphragms are provided by springs 25 and 26,respectively. Spindles 21 and 28, respectively, connect the diaphragmswith a second inhalation valve 29 and a second exhalation valve 30,respectively.

The inhalation valve chamber 2| is connected by means of the inhalationconduit 3| with the respiration mouth piece 32 and by this with thelungs, as schematically outlined at 33. From the inhalation conduit 3| apressure equalizer conduit 34 communicates with'the diaphragm chamber 24of the exhalation valve 20. Exhalation conduit 35 connects the valvechamber 22 of the exhalation valve 20 with the respiration mouth piece32, and a pressure equalizer conduit 36 establishes communicationbetween conduit 35 and the diaphragm chamber 23 of the inhalation valveI8.

An electric heater 3'! is arranged in connection with inhalation conduit3|, and may also effect the gasification of narcotics in a reservoir 38.The temperature is measured by the thermometer 39. If desired, theinhaling gas may be moistened in the container 40. The level ofrespiration is read off on the manometer 4|, arranged in one of thepressure equlizer conduits, for instance in the conduit 36.

The device works in the following way. Assume that all valves are in thepositions shown in the figure. The gas flows from the cylinder throughthe reducing valve 2, the pressure governor 3, the equlizer 4 and theconduit 5 with the throttle 6 to the chamber above the wall IS. Thevalves 8 and 29 being open, the gas continues through the conduit H, thevalve chamber 2|, the conduit 3| and the mouth piece 32 to the lungs 33,which during a period of increasing elastic tension caused by theirexpansion, are filled with 5 fresh gas. The pressure of fluid beingdelivered to the lungs is transmitted to the diaphragm chambers 23 and24 by means of the pressure equalizer conduits 36 and 34. A relativelysmall pressure increase causes the valve 30 to be opened by thediaphragm connected therewith. At first, however, this has no effect, asthe valve 9 is still closed.v When the maximum pressure of the lung hasbeen attained, the valve 29 is closed by its diaphragm.

The closing of valve 29 causes the pressure in the chamber above thewall I6 to increase very rapidly, and the gas, after having attained acertain pressure, flows into the pressure chamber I!) through the valvel3. After a short time, for instance 6 of a second, the valve spindle I2is suddenly moved upwardly, thus closing the valve 8 and opening thevalve 9.

The exhalation period now begins, the consumed gas leaving the lungs 33through the mouth piece 32, the conduit 35 and the valves 30 and 9. Byclosing the valve 8, the gas supply to the pressure chamber III has beencut oil. Thereafter, the gas will be slowly discharged from this chamberthrough the conduit l4 and the throttle I5. A short time after theexhalation period has begun the valve 29 is opened due to the reducedpressure in diaphragm chamber 23, but this, how- 40 able for thispurpose.

reached, and the exhalation periodstops. The

. valve 29 and the valve 30 are now in their proper positions for thestart of the next'respiration cycle, and this begins immediately, whenthe pressure in the pressure chamber ID has fallen sumciently for themechanism I I to move spindle l2 downwardly to open valve 8 and closevalve 9. The respiration cycle is now repeated in the .same manner asabove described.

It will be seen that the frequency of the periods may be regulated byadjusting throttle l5 the maxlmum pressure at theend of the inhalationperiod can be arbitrarily regulated by adjusting spring 25. In acorresponding way the positive. minimum pressure, which stops theexhalation period, may be adjusted by means of the spring 26. Normally,a relatively smallamount of gas is delivered between these two positionsand consequently the movements of the lungs are relatively small, whichis necessary in order not to disturb the physician in his operation. Theapparatus, as above described, is

therefore not suitable as a reviving apparatus, partly for the reasonthat it causes too small respiration movements of the lungs, and partlyon account of its respiration level being unsuit- However, the apparatuscan-be easily adjusted so as to serve for reviving purposes. Two handles42 and 43 are arranged inconnection with the inhalation valve l8 and theexhalation valve 20, respectively. By

means of the handle 42 an additional spring 44 may be rendered effectiveby means of which the maximum pressure may be increased to a valuesuitable for reviving apparatus. The handle 43 is arranged to lock thevalve 3|] in o en 0 position so that the exhalation is unimpeded.

If the respiration muscles of. the patient are able to function even toan insignificant degree,

the patient unconsciously reacts against a wrong 3 respirationperiodicity by movements that couri- 55f teract the normal period of therespiration of the apparatus. The respiration apparatus is Q sensitiveto such re-synchronizing impulses. For this purpose, a valve 46,auxiliary to the exhala- Ition valve 30, is provided. These two valvesare oiliconnected witheach other and with the diaphragm 45 by means of alever 41 so arranged gthat inward movement of the diaphragm firstcompletely closes valve 30, provided that the valve 30 is not locked,without actuating valve 65 46, but further movement of the diaphragmrapidly opensvalve 46. In case the valve 30 is' locked, and'theapparatus is working as a reviving apparatus, the diaphragm 45immediately opens valve 46. The valve 46 is arranged in a 70 conduit 48,which connects the pressure cham- 75 apparatus, a vacuum is produced inthe lungs 33 which is transmitted by the conduit 3| and the equalizerconduit 34 to the diaphragm chamber 24. This vacuum causes the diaphragm-46 to move inwardly sufficiently to open the valve 46.

Either the exhalation period of the apparatus has already been stoppedby the normal closing of the valve 30 or this valve is closed by the'movement of the diaphragm caused by the attempted inhalation. Thepressure chamber III is immediately emptied by the opening of valve 46and the mechanism II closes the valve 9 and opens valve 8, therebystarting a normal inhalation period. The re-synchronizing has, in thismanner, been eifected.

If the re-synchronizing takes place during a period of inhalation of theapparatus by an attempted exhalation of the patient, the conduit 35 andthe pres-sureequalizer conduit 36 transmit an immediate excess ofpressure to the diaphragm chamber 23, which causes the valve 29 toclose. A corresponding excess of. pressure is transmitted by the conduit31 and the pressure equalizer conduit 34 to the diaphragm chamber '24 ofthe valve housing 20. The valve 30 is immediately opened thereby, andthe valve 46, should it have been opened, is closed. In this way thepassage between the pressure chamber i0 and the atmosphere at valve 46is closed (throttle i5 remains open), and the valves 8 and 9 are movedto their proper position for the beginning of an exhalation period.Thus, in this case, a complete resynchronizing has been e1- fected.

While we have shown and described one preferred embodiment of ourinvention, it is to be understood that this has been done for purposesof illustration only, and that the scope of our invention is not to belimited thereby, but is to be determined by the appended claims viewedin the light of the prior art.

What we claim is:

1. In a respiration apparatus, means for stepping an inhalation periodat a maximum positive pressure, means for stopping an exhalation periodat a minimum positive pressure to thereby constantly maintain positivepressure in said ap-- paratus while said apparatus is in use, andpressure responsive means for actuating said means.

2. In a respiration apparatus, a valve for stepping an inhalationperiod, means for closing said valve responsive to a maximum positivepressure, a valve for stopping an exhalation period, and means forclosing the last-mentioned valve responsive to a minimum positivepressure to thereby constantly maintain positive pressurein saidapparatus while said apparatus is in use.

3. In a respiration apparatus, a mouthpiece, an inhalation conduitconnected to said mouthpiece, an inhalation valve in said conduit, afirst diaphragm for actuating said valve, an exhalation conduitconnected to said mouthpieceyan exhalation valve in said exhalationconduit, and a second diaphragm for actuating said exhalation valve,said first diaphragm being responsive to an increase in pressure in saidmouthpiece to close said inhalation valve and said second diaphragmbeing responsive to an increasein pressure in said mouthpiece to opensaid inhalation valve, each of said diaphragms acting independently orthe other.

4. In a respiration apparatus, a mouthpiece, an inhalation conduitconnected to. said mouthpiece, an inhalation valve in said conduit, afirst diaphragm for actuating said valve, an exhalation ,conduitconnected to said mouthpiece, an exunder pressure, a mouthpiece, aninhalation conhalation valve in said exhalation conduit, and a seconddiaphragm for actuating said exhalation valve, both of said diaphragmsbeing subjected directly to fluid pressure, said first diaphragm beingresponsive to an increase in pressure in said exhalation conduit toclose said inhalation valve and said second diaphragm being responsiveto an increase in pressurein said inhalation conduit to open saidexhalation valve.

5. In a respiration apparatus, a mouthpiece, an inhalation conduitconnected to said mouthpiece, an inhalation valve in said conduit, afirst diaphragm for actuating said valve, an exhalation conduitconnected to said mouthpiece, an exhalation valve in said exhalationconduit, a second diaphragm for actuating said exhalation valve, each ofsaid diaphragms acting independently of the other to actuate therespective valves independently, said first diaphragm being responsiveto an increase in pressure in said mouthpiece to close said inhalationvalve and said second diaphragm being responsive to an increase in thepressure in said mouthpiece to open said exhalation valve, and means forcontrolling the frequency of the actuation of said valves by saiddiaphragms.

6. In a respiration apparatus, a mouthpiece, aninhalation conduitconnected to said mouthpiece, an inhalation valve in said conduit, afirst diaphragm for actuating said valve, an exhalation conduitconnected to said mouthpiece, an exhalation valve in said exhalationconduit, a second diaphragm for actuating said exhalation valve, saidfirst diaphragm being responsive to an increase in pressure in saidmouthpiece to close said inhalation valve and said second diaphragmbeing responsive to an increase in pressure in said mouthpiece to opensaid exhalation valve, and means operative upon an. increase in pressureWithin said mouthpiece for controlling the frequency of the actuation ofsaid valves by said diaphragms.

'1. In a respiration apparatus, a source of gas under pressure, amouthpiece, an inhalation conduit connecting said source with saidmouthpiece, a first inhalation valve and a second inhalation valve insaid conduit, an exhalation conduit connecting said mouthpiece with theatmosphere, a first exhalation valve and a second exhalation valve insaid exhalation .conduit, means for closing said first inhalation valvein response to an increase in pressure in said mouthpiece, means foropening said first exhalation valve in response to an increase inpressure in said mouthpiece, and means operative upon an increase in thepressure within said mouth piece for simultaneously closing said secondinhalation valve and opening said second exhalation valve.

8. In a respiration. apparatus, a source of gas duit connecting saidsource with said mouthpiece, a first inhalation valve and a secondinhalation valve in said conduit, an exhalation conduit connecting saidmouthpiece with the atmosphere, a first exhalation valve and a secondexhalation valve in said exhalation conduit, means for closing saidfirst inhalation valve in response to an increase in pressure in saidmouthpiece, means for opening said first exhalation valve in response toan increase in pressure in said mouthpiece, means forming ,a pressurechamber connected to said inhalation conduit between said first and.second inhalation valves, a one-way valve opening from said inhalationconduit into said chamber, throttling means connecting said chamber withthe atmosphere, and means responsive to an increase in pressure in saidchamher for simultaneously closing said second inhalation valve andopening said second exhalation valve.

9. In a respiration apparatus, a source of gas under pressure, amouthpiece, an inhalation conduit connecting said source with saidmouthpiece, a first inhalation valve and a second inhalation valve insaid conduit, an exhalation conduit connecting said mouthpiece with theatmosphere, a first exhalation valve and a second exhalation valve insaid exhalation conduit, means for closing said first inhalation valvein response to an increase in pressure in said mouthpiece, means foropening said first exhalation valve in response to an increase inpressure in said mouthpiece, means forming a pressure chamber connectedto said inhalation conduit between said first and second inhalationvalves, a one-way pressure responsive valve opening from said inhalationconduit into said chamber, said first inhalation valve being arranged toclose at a lower pressure than is required to open said oneway valve,throttling means connecting said chamber with the atmosphere, and meansresponsive to an increase in pressure in said chamher for simultaneouslyclosing said second inhalation valve and opening said second exhalationvalve.

10. In a respiration apparatus, a valve for stopping an inhalationperiod, means for closing said valve responsive to a maximum positivepressure, a valve for stopping an exhalation period, and means forclosing the last-mentioned valve responsive to a minimum positivepressure, either of said means being adiustable so as to be operative atdifferent pressures. 11. In a respiration apparatus, a valve forstopping an inhalation period, a spring-pressed diaphragm for closingsaid valve responsive to a maximum positive pressure, additional springmeans, means for rendering said additional spring means operative toincrease the value of the pressure at which said diaphragm responds toclose said valve, a valve for stopping an exhalation period, and meansfor closing the last-mentioned valve responsive to a minimum positivepressure.

12. In a respiration apparatus, a valve for stopping an inhalationperiod, means for closing said valve responsive to a maximum positivepressure, a valve for stopping an exhalation period, means for closingsaid valve responsive to a minimum positive pressure, and means formaintaining the last mentioned valve open against the action of thesecond-mentioned means.

13. In a respiration apparatus, a valve for stopping an inhalationperiod, a spring-pressed diaphragm for closing said valve responsive toa maximum positive pressure, additional spring means, means forrendering said additional spring means operative to increase the valueof the pressure at which said diaphragm responds to close said valve, avalve for stopping an exhalation period, means for closing thelast-mentioned valve responsive to a minimum positive pressure, andmeans for maintaining said last-mentioned valve open against the actionof the last-mentioned means.

14. In a respiration apparatus, a source of gas under pressure, amouthpiece, an inhalation cn piece, an inhalation valve in said conduit,an

exhalation conduit'connecting said mouthpiece exhalation valve,

with the atmosphere,an exhalation valve in said exhalation conduit, apressure chamber, means responsive toa normalincrease in pressure insaid mouthpiece for admitting gas under pressure to said chamber, meansresponsive-to an increase in pressure in said chamber for simultaneouslyclosing said inhalation valve and opening said exhalationvalve, andmeans responsive to an abnormal reduction of pressure in said mouthpiecefor reducing the pressure in said chamber. I

15. In a respiration apparatus, a source of gas under pressure, amouthpiece, aninhalation conduit connecting said source with saidmouthpiece, a first inhalation valve and a. second inhalation valve insaid conduit, an exhalation conduit connecting said mouthpiece with theatmosphere, a. first exhalation valve and a second exhalation valve insaid exhalation conduit, a first diaphragm for closing said firstinhalation valve 35 chamber to the atmosphere, a valve in the last-vmentioned conduit, and means operatively connecting said seconddiaphragm with the lastmentioned valve for opening said last mentionedvalve in response to an abnormal reduction of pressure in saidmouthpiece. 7

16. In a respiration apparatus, a source of gas under pressure, amouthpiece, an inhalation conduitv connecting said source with saidmouthpiece, a first inhalation valve and a second inhalation valve insaid conduit, an exhalation conduit connecting said mouthpiece with theatmosphere, a first exhalation valve and a second exhalation valve insaid exhalation conduit, a first diaphragm for opening said firstinhalation valve in response to a normal decrease of pressure in saidmouthpiece, a pressure chamber, means responsive to a normal increase ofpressure in said mouthpiece for admitting gas under pressure to saidchamber, means responsive' to an increase of pressure in said chamberfor simultaneously closing said second inhalation valve and opening.said second exhalation valve, a conduit connecting said chamber to theEMIL EINAR WILHELM ANDERSON. GEORG KARL JOHANSSON.

